The present invention relates to a method for diagnosing psychiatric disorders by monitoring the pattern of a subject's heart rate, and more particularly to a method for diagnosing psychiatric disorders by monitoring at least a portion of a subject's circadian heart rate pattern. The present invention also provides a method for assessing the effectiveness of treatments for psychiatric disorders.
Despite intensive research for nearly a century, there is still no reliable `laboratory test` for mental illness. Diagnoses are still made `clinically`, on the basis of subjective experience [symptoms] and observed behaviour [signs]. Given the difficulties of defining normal experience and behaviour and the lack of any reliable objective indicators, it is not surprising that to date, all systems of diagnosis/classification in psychiatry have been less than satisfactory for one reason or another. A reliable laboratory test would be of enormous practical value in everyday clinical practice and contribute greatly to advancement in theory and practice more generally.
It is suggested that hitherto attempts to find `laboratory indicators` of mental illness have failed because of their conceptually misguided approach. Previous researchers have tended to look for some `fixed` chemical/anatomical lesion in the brain, in imitation of a neurological or neuropathological approach. If, however, there is no such `fixed` lesion, but rather a functional disregulation, [like a `tuning problem` in a car and TV set], then the neuropathological approach is doomed to failure.
The present invention seeks to provide a method for diagnosing psychiatric disorders or to at least provide a diagnostic method that may provide objective indications of clinical status and change and contribute to the diagnostic assessment of a subject.